Allow internal macros without prefix
Allow internal macros without prefix

Internal macros are not present as symbols, visible or usable outside
the compilation unit and it is safe to allow them to have a name without
namespace prefix.

We also allow them to start with lower case letters as some of our
internal macros already have names like that.

Signed-off-by: Janos Follath <b175c17abe0474719672be1367bb75ee28bd5c71@arm.com>

ARMmbed/mbedtls,ARMmbed/mbedtls,Mbed-TLS/mbedtls,ARMmbed/mbedtls,ARMmbed/mbedtls,Mbed-TLS/mbedtls,Mbed-TLS/mbedtls,Mbed-TLS/mbedtls